| /* |
| * Copyright 2018-present Open Networking Foundation |
| |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package adaptercore |
| |
| import ( |
| "reflect" |
| "runtime" |
| |
| "github.com/opencord/voltha-go/common/log" |
| ) |
| |
| // DeviceState OLT Device state |
| type DeviceState int |
| |
| const ( |
| // deviceStateNull OLT is not instantiated |
| deviceStateNull DeviceState = iota |
| // deviceStateInit OLT is instantiated |
| deviceStateInit |
| // deviceStateConnected Grpc session established with OLT |
| deviceStateConnected |
| // deviceStateUp Admin state of OLT is UP |
| deviceStateUp |
| // deviceStateDown Admin state of OLT is down |
| deviceStateDown |
| ) |
| |
| // Trigger for changing the state |
| type Trigger int |
| |
| const ( |
| // DeviceInit Go to Device init state |
| DeviceInit Trigger = iota |
| // GrpcConnected Go to connected state |
| GrpcConnected |
| // DeviceUpInd Go to Device up state |
| DeviceUpInd |
| // DeviceDownInd Go to Device down state |
| DeviceDownInd |
| // GrpcDisconnected Go to Device init state |
| GrpcDisconnected |
| ) |
| |
| // TransitionHandler function type for handling transition |
| type TransitionHandler func() error |
| |
| // Transition to store state machine |
| type Transition struct { |
| previousState []DeviceState |
| currentState DeviceState |
| before []TransitionHandler |
| after []TransitionHandler |
| } |
| |
| // TransitionMap to store all the states and current device state |
| type TransitionMap struct { |
| transitions map[Trigger]Transition |
| currentDeviceState DeviceState |
| } |
| |
| // OpenoltDevice state machine: |
| // |
| // null ----> init ------> connected -----> up -----> down |
| // ^ ^ | ^ | | |
| // | | | | | | |
| // | +-------------+ +---------+ | |
| // | | |
| // +-----------------------------------------+ |
| |
| // NewTransitionMap create a new state machine with all the transitions |
| func NewTransitionMap(dh *DeviceHandler) *TransitionMap { |
| var transitionMap TransitionMap |
| transitionMap.currentDeviceState = deviceStateNull |
| transitionMap.transitions = make(map[Trigger]Transition) |
| // In doInit establish the grpc session |
| transitionMap.transitions[DeviceInit] = |
| Transition{ |
| previousState: []DeviceState{deviceStateNull}, |
| currentState: deviceStateInit, |
| before: []TransitionHandler{dh.doStateInit}, |
| after: []TransitionHandler{dh.postInit}} |
| // If gRpc session fails, re-establish the grpc session |
| transitionMap.transitions[GrpcDisconnected] = |
| Transition{ |
| previousState: []DeviceState{deviceStateConnected, deviceStateDown}, |
| currentState: deviceStateInit, |
| before: []TransitionHandler{dh.doStateInit}, |
| after: []TransitionHandler{dh.postInit}} |
| // in doConnected, create logical device and read the indications |
| transitionMap.transitions[GrpcConnected] = |
| Transition{ |
| previousState: []DeviceState{deviceStateInit}, |
| currentState: deviceStateConnected, |
| before: []TransitionHandler{dh.doStateConnected}} |
| |
| // Once the olt UP is indication received, then do state up |
| transitionMap.transitions[DeviceUpInd] = |
| Transition{ |
| previousState: []DeviceState{deviceStateConnected, deviceStateDown}, |
| currentState: deviceStateUp, |
| before: []TransitionHandler{dh.doStateUp}} |
| // If olt DOWN indication comes then do sate down |
| transitionMap.transitions[DeviceDownInd] = |
| Transition{ |
| previousState: []DeviceState{deviceStateUp}, |
| currentState: deviceStateDown, |
| before: []TransitionHandler{dh.doStateDown}} |
| |
| return &transitionMap |
| } |
| |
| // funcName gets the handler function name |
| func funcName(f interface{}) string { |
| p := reflect.ValueOf(f).Pointer() |
| rf := runtime.FuncForPC(p) |
| return rf.Name() |
| } |
| |
| // isValidTransition checks for the new state transition is valid from current state |
| func (tMap *TransitionMap) isValidTransition(trigger Trigger) bool { |
| // Validate the state transition |
| for _, state := range tMap.transitions[trigger].previousState { |
| if tMap.currentDeviceState == state { |
| return true |
| } |
| } |
| return false |
| } |
| |
| // Handle moves the state machine to next state based on the trigger and invokes the before and |
| // after handlers |
| func (tMap *TransitionMap) Handle(trigger Trigger) { |
| |
| // Check whether the transtion is valid from current state |
| if !tMap.isValidTransition(trigger) { |
| log.Errorw("Invalid transition triggered ", log.Fields{"CurrentState": tMap.currentDeviceState, "Trigger": trigger}) |
| return |
| } |
| |
| // Invoke the before handlers |
| beforeHandlers := tMap.transitions[trigger].before |
| if beforeHandlers != nil { |
| for _, handler := range beforeHandlers { |
| log.Debugw("running-before-handler", log.Fields{"handler": funcName(handler)}) |
| if err := handler(); err != nil { |
| // TODO handle error |
| return |
| } |
| } |
| } else { |
| log.Debugw("No handlers for before", log.Fields{"trigger": trigger}) |
| } |
| |
| // Update the state |
| tMap.currentDeviceState = tMap.transitions[trigger].currentState |
| log.Debugw("Updated device state ", log.Fields{"CurrentDeviceState": tMap.currentDeviceState}) |
| |
| // Invoke the after handlers |
| afterHandlers := tMap.transitions[trigger].after |
| if afterHandlers != nil { |
| for _, handler := range afterHandlers { |
| log.Debugw("running-after-handler", log.Fields{"handler": funcName(handler)}) |
| if err := handler(); err != nil { |
| // TODO handle error |
| return |
| } |
| } |
| } else { |
| log.Debugw("No handlers for after", log.Fields{"trigger": trigger}) |
| } |
| } |